java考试题型及作业(13)

必考题。

exit.addActionListener(this);

addWindowListener(new WindowAdapter()

{ public void windowClosing(WindowEvent e)

{ System.exit(0);

}

});

setJMenuBar(mb);

show();

}

public void actionPerformed(ActionEvent e)

{

System.exit(0);

}

public static void main (String[] args)

{

new ex3_3();

}

}

4、创建一个窗口，单击“提示”按钮可出现一个写有“你好！”文字的对话框。 import java.awt.*;

import javax.swing.*;

import java.awt.event.*;

public class ex3_4 implements ActionListener

{

JButton bt=new JButton("对话框");

JFrame jf=new JFrame("有对话框的窗口");

public ex3_4()

{

Container c=jf.getContentPane();

c.add(bt,BorderLayout.SOUTH);

bt.addActionListener(this);

jf.addWindowListener(new WindowAdapter()

{ public void windowClosing(WindowEvent e)

{ System.exit(0);

}

});

jf.setSize(300,300);

jf.show();

}

public void actionPerformed(ActionEvent e)

{

JOptionPane.showOptionDialog(jf,"你好","我是自定义对话框",JOptionPane.DEFAULT_OPTION,JOptionPane.ERROR_MESSAGE,null,null,null);